User manual

Page 88 Bottle Mode – PAT700 Total Organic Carbon Analyzer
Operator Manual Anatel
6.5 TOC calibration
TOC calibration ensures the accuracy of the TOC values obtained by the analyzer. TOC
values are determined by measuring the change in conductivity of a high-purity water sample
as its organic compounds oxidize to carbon dioxide inside the analysis cell. The procedure
subtracts the average of a series of background TOC measurements from the average of a
series of user-selected standard measurements (in the form of sucrose). Linear regression is
performed on the data, and the correlation coefficient (R
2
) and percent slope change (% sc)
are calculated and reported.
The recommended correlation coefficient, a user-accepted value (R
2
), is 0.990 or greater.
The calibration will be accepted if the R
2
value is 0.990 or greater and the percent slope
change is within the specified ±15% limit.
TOC calibration setup
Figure 6-3 TOC calibration setup dialog box
Use default settings and use custom settings radio buttons enable you to select default
settings or custom settings. The default selection is use default settings.
Back icon takes you back to the previous dialog box. All changes made to the TOC
calibration are retained.
Forward icon takes you to the next dialog box.
• If you select default settings, the load bottles dialog box opens.
See Figure 6-5.
• If you select custom settings, the custom setup dialog box opens. See Figure 6-4. If
you select custom settings and then touch the back button, the analyzer uses the
default settings.
• All changes made to the TOC calibration are retained.
Cancel icon returns you to the run standards dialog box. All changes made in any of the
dialog boxes are lost.